Thisa known issue to those who use the Kitchen more than me, but the stove has developed an issue where if the lower over is on, there is an updraft through the stove burners that blows out the flame of the burner and causes unburned gas to flow out. This is quite unsafe and posses an explosion risk.
I have not looked into what is causing the issue, but based on the ago the the stove, I'd suggest it might be appropriate to simply replace it.
Quick searching, we can get a more modern good quality gas stove used for $150-$300. Should we put up a vote for a budget and see what deals we can find?